title: Radioactive cesium (¹³⁴Cs and ¹³⁷Cs) content in human placenta after the Fukushima nuclear power plant accident.
abstract: OBJECTIVE
  The degree of contamination with radioactive cesium (¹³⁴Cs and ¹³⁷Cs) in the human placenta after the accident at Fukushima nuclear power plant (FNP), which occurred on 11 March 2011, has not been assessed.
  
  
  METHODS
  ¹³⁴Cs and ¹³⁷Cs contents were determined in 10 placentas from 10 women who gave birth to term singleton infants during the period between October 2011 and August 2012 using high-purity germanium detectors for gamma ray spectrometry. Five women resided within 50 km of FNP (neighbor group) and gave birth by the end of February 2012, while the other five women resided within 210-290 km of FNP (distant group) and gave birth in July and August 2012.
  
  
  RESULTS
  All except one of the 10 placentas contained detectable levels of ¹³⁴Cs and ¹³⁷Cs, ranging 0.042-0.742 Bq/kg for ¹³⁴Cs and 0.078-0.922 Bq/kg for ¹³⁷Cs. One placenta from a woman living in Tokyo contained 0.109 Bq/kg ¹³⁷Cs and no detectable level of ¹³⁴Cs (<0.054 Bq/kg). ¹³⁷Cs content was more than 0.2 Bq/kg in four and one placentas in the neighbor and distant groups, respectively.
  
  
  CONCLUSIONS
  Degree of contamination of the placenta with radioactive Cs was lower even in women who resided within 50 km of FNP compared to Japanese and Canadian placentas in the mid-1960s after repeated nuclear tests and in northern Italian placentas from 1986-1987 after the Chernobyl power plant accident.
authors.affiliation: Department of Obstetrics and Gynecology, Kameda General Hospital, Kamogawa, Chiba, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Suzuki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Terada
authors.forename: Nobuya
authors.initials: N
authors.lastname: Unno
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yamaguchi
authors.forename: Naoki
authors.initials: N
authors.lastname: Kunugita
authors.forename: Hisanori
authors.initials: H
authors.lastname: Minakami
mesh_terms: D000328:Adult; D002588:Cesium Radioisotopes / Q000032:analysis*; D004784:Environmental Monitoring; D005260:Female; D062406:Fukushima Nuclear Accident; D006801:Humans; D007564:Japan; D010920:Placenta / Q000737:chemistry*; D011247:Pregnancy; D011848:Radioactive Pollutants / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D011848:Radioactive Pollutants
keywords: cesium; human placenta; nuclear power plant accident